Top JavaScript Interview Questions [2024]
Javascript is widely used around the world to build web applications. Interviewing Javascript candidates commonly consists of basic and advanced questions to assess technical ability. We sourced these questions from the JavaScript community based on developers’ own interview experience and what our clients found important to ask. Could you use help hiring JavaScript developers? Scalable Path’s experienced Talent Acquisition team can help.
JavaScript Interview Questions and Answers
These are the types of questions typically asked during Javascript interviews. We created them to help you test your understanding of the popular programming language, or guide your initial technical screening with Javascript candidates.
What is the difference between var, let and const keywords?View Answer
Which variable declaration keyword is most preferable for use as a for loop counter?View Answer
How are arrow function declarations different from traditional function declarations?View Answer
How is concurrency achieved in JavaScript?View Answer
In `setTimeout(() => console.log("hello world")}, 0);` console.log might not execute immediately. What is the reason for that?View Answer
What are Promises?View Answer
What are the three states of a Promise?View Answer
What does the fetch function do?View Answer
What are mutable and immutable data types in JavaScript? Which data types are immutable?View Answer
What is the implication of having functions as first-class citizens in JavaScript?View Answer
What is a pure function in JavaScript? Why it is desirable?View Answer
What do "passed by reference" and "passed by value" refer to in JavaScript?View Answer
What is a closure in JavaScript? What could it be used for?View Answer
What does the strict mode (useStrict) do?View Answer
What is a constructor function? How do you call a constructor function?View Answer
What are the advantages and disadvantages of using TypeScript?View Answer
What is your preference between using jQuery or Vanilla JavaScript?View Answer
What could be some ways of dealing with CPU-intensive tasks in the browser?View Answer
What are some things that you should pay attention to while loading JavaScript files in the browser.View Answer
What programming paradigm does JavaScript support?View Answer
This list isn't exhaustive, and interviewing typically includes an assessment of soft skills and technical ability through a take-home assignment or live coding exercise. You can learn more about hiring here.
